Fix Release Notes for 0.17.4
Fix Release Notes for 0.17.4

It appears that the list of issues fixed in Release Notes for 0.17.4 is
a straight copy of 0.17.3. A `git diff v0.17.3..v0.17.4` and a little
annotate later turned up these fixed issues instead.

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt